Re: [dev] [dwm] strange issue with gedit and multiple screens

From: Anselm R Garbe <garbeam_AT_gmail.com>
Date: Sun, 15 Apr 2012 11:42:35 +0200

On 13 April 2012 19:12, Martti Kühne <mysatyre_AT_gmail.com> wrote:
> after whining earlier on irc, I've got to put things straight here.
> I have two monitors and most of the time I don't really care where the mouse
> pointer is. using dwm with multiple monitors works great, as there is the
> focusmon function, which I have assigned to a key to switch between monitors.
>
> The issue I was having with gedit was this: every now and then, gedit would
> refuse to display a text cursor when I use the mouse to point, click and, at
> the same time, get focus from a different screen. The only way of knowing where
> in the text the cursor was, was to blindly type something or press the focusmon
> key twice, which worked as a workaround for the issue.
>
> In the course of debugging this I also noticed the same can be achieved when
> the focusmon key is used to switch to a window on the other screen and follow
> with the mouse and come back again, returning focus to the screen where gedit
> runs. Again, input is taken, blue border is drawn, but no text cursor is shown.
>
> Well, I can imagine that it's easy to blame gedit for that inconsistency,
> apparently qt applications do not suffer from this.
>
> Anyway, looking at dwm's codebase it isn't really clear when focus() is called,
> selmon is set and unfocus is called, and, focus() itself calls unfocus and sets
> selmon just in case. Needless to say, it made debugging a horrible task here.

True, the focus handling is one of the most sucking parts of dwm and X ;)

> I have tried quite a lot of things which ultimately lead to the desired
> behavior, and then tested things hunkwise to find the culprit after all;
> turns out it's my regular use of focusmon() which actually triggers the bug in
> the first place; the change that solved my issues can be found in [1].
>
> tl:dr; improve focus behavior of at least anjuta and gedit [1]

Applied for now, looking forward that someone starts whining that the
next X client is broken now.

Cheers,
Anselm
Received on Sun Apr 15 2012 - 11:42:35 CEST